Plasma display apparatus

ABSTRACT

A plasma display apparatus is equipped with a signal input terminal responsive to a user&#39;s application. The plasma display apparatus includes a panel including a pair of substrates, wherein at least one of the substrates is transparent. The substrates are placed opposite to each other to form a discharge space in between, and electrodes are provided to the substrate. The plasma display apparatus also includes a display driving circuit block, disposed on a chassis and equipped with at least one signal inputting connector which applies a signal to the panel to perform displaying, and an input signal circuit block detachable to the signal inputting connector of the display driving circuit block.

This application is a divisional application of application Ser. No.10/311,433, which is a U.S. national stage application of InternationalApplication Serial No. PCT/JP02/05841, filed Jun. 12, 2002.

TECHNICAL FIELD

The present invention relates to plasma display apparatuses which arethin, light weight, and have a large display area.

BACKGROUND ART

Plasma display apparatuses are widely used as display apparatusesinstalled in busy sections of a city for the general public, orinstalled at a home for a family to enjoy videos on a large screen. Aplasma display panel (PDP) has better characteristics than a liquidcrystal panel in the following points: responding at a faster speed, awider viewing angle, easier to produce a larger screen, and higherdisplay quality due to self-light-emitting.

In the PDP, display cells partitioned with barrier ribs are disposed ona board, and a phosphor layer covers the display cells. An ultravioletray generated by gas discharge excites the phosphor to emit light forcolor display.

The PDP is largely classified into an alternating current (AC) drivingsystem and a direct current (DC) driving system, and into a surfacedischarge and an opposite discharge. A three-electrodes, AC driving andsurface discharge PDP takes the mainstream of the PDP because of itshigh resolution, easiness of producing a large screen and easiness offabrication. This PDP comprises the following elements:

a first substrate having a pair of display electrodes adjacent to eachother in parallel; and

a second substrate having address electrodes arranged in a directioncrossing the display electrodes, barrier ribs and a phosphor layer. Thisstructure allows the phosphor layer to be rather thick, and is suitablefor color display.

On the other hand, the PDP can be used as a large size display invarious applications, so that its input signal terminal is desirablyconnectable to various external apparatuses such as a personal computer,a television receiver, and a video cassette recorder. Those apparatusesoutput their video signals including information signals.

A plasma display apparatus is thus equipped with varioussignal-input-terminals to receive as many external signals as possible.Users in the consumer market, however, scarcely use every signal-inputterminal, but use one specific terminal for a particular externalapparatus. Therefore, a number of the various signal-input terminals areuseless for the users in the consumer market.

Plural types of plasma display apparatuses may be produced so thatparticular signal-input terminals responsive to users' applications canbe provided. However, there will be a lot of models of one productbecause of the many applications discussed above, which lowers theproductivity.

The present invention addresses the foregoing problem and aims toprovide with ease a plasma display apparatus having a signal-inputterminal responsive to a user's application.

SUMMARY OF THE INVENTION

The plasma display apparatus of the present invention comprises thefollowing elements to overcome the problem discussed above:

a panel;

a display driving circuit block, disposed in a chassis, for applying asignal to the panel to display;

an input signal circuit block coupled between the display drivingcircuit block and an external apparatus which outputs video signals; and

a housing that accommodates the panel, the display driving circuit blockand the input signal circuit block.

The input signal circuit block includes the following elements:

a case disposed in the chassis and having a mounting port open tooutside of the housing;

a signal outputting connector detachably mounted to the case at themounting port, whereby the connector is coupled detachably to a signalinputting connector of the display driving circuit block; and

a block unit having an input terminal section to which a connectingcable to an external apparatus can be coupled detachably.

This structure allows for the preparation of a number of block unitshaving an input terminal section responsive to an external apparatus tobe coupled to the plasma display apparatus. The block unit can bereplaced with another one that is responsive to a user's request, sothat the plasma display apparatus equipped with a signal input terminalappropriate to an application can be prepared with ease.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective sectional view illustrating a schematicstructure of a PDP of a plasma display apparatus in accordance with anexemplary embodiment of the present invention.

FIG. 2 illustrates arrays of electrodes of the PDP of the plasma displayapparatus in accordance with the exemplary embodiment of the presentinvention.

FIG. 3 shows a signal waveform for driving the plasma display apparatusin accordance with the exemplary embodiment of the present invention.

FIG. 4 is an exploded perspective view illustrating an inside of theplasma display apparatus in accordance with the exemplary embodiment ofthe present invention.

FIG. 5 is a plan view illustrating a placement of elements on a chassisof the plasma display apparatus in accordance with the exemplaryembodiment of the present invention.

FIG. 6 is a plan view illustrating a structure of an input signalcircuit block of the plasma display apparatus in accordance with theexemplary embodiment of the present invention.

FIG. 7 is an exploded perspective view illustrating a structure of theinput signal circuit block and a control circuit block of the plasmadisplay apparatus in accordance with the exemplary embodiment of thepresent invention.

FIG. 8 is a perspective view, viewed from the bottom, illustrating astructure of a case of the input signal circuit block of the plasmadisplay apparatus in accordance with the exemplary embodiment of thepresent invention.

FIG. 9 shows a top view of a block unit of the input signal circuitblock of the plasma display apparatus in accordance with the exemplaryembodiment of the present invention.

FIG. 10 shows a bottom view of the block unit of the input signalcircuit block of the plasma display apparatus in accordance with theexemplary embodiment of the present invention.

FIG. 11 shows a lateral view of the block unit of the input signalcircuit block of the plasma display apparatus in accordance with theexemplary embodiment of the present invention.

FIG. 12 shows a back view of the block unit of the input signal circuitblock of the plasma display apparatus in accordance with the exemplaryembodiment of the present invention.

FIG. 13 shows a front view of the block unit of the input signal circuitblock of the plasma display apparatus in accordance with the exemplaryembodiment of the present invention.

FIG. 14 is a detailed sectional view of section A of the block unitshown in FIG. 9.

FIG. 15 is a detailed sectional view of section B of the block unitshown in FIG. 9.

FIG. 16(a) through FIG. 16(f) are plan views illustrating other examplesof input terminals of the input signal circuit block of the plasmadisplay apparatus in accordance with the exemplary embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

An exemplary embodiment of the present invention is demonstratedhereinafter with reference to the accompanying FIG. 1 through FIG. 16.The present invention is not limited to this embodiment.

A structure of a plasma display panel (PDP) of a plasma displayapparatus is described with reference to FIG. 1. As shown in FIG. 1, atransparent front substrate 1, such as a glass substrate, has pluralrows of stripe-shaped display electrodes 2 as pairs of a scan electrodeand a sustain electrode formed thereon. Dielectric layer 3 covers theelectrodes, and protective film 4 is formed on top of dielectric layer3.

A back substrate 5, disposed opposite to the front substrate 1, hasplural rows of address electrodes 7 shaped like stripes formed thereon,such that they cross with display electrodes 2 forming the scan andsustain electrodes. Overcoat layer 6 covers address electrodes 7. On topof overcoat layer 6, plural barrier ribs 8 are prepared between and inparallel with address electrodes 7. Phosphor layer 9 is disposed onlateral faces of barrier ribs 8 and on the surface of overcoat layer 6.

Front substrate 1 and back substrate 5 are placed opposite to each otherwith a fine discharge space therebetween such that display electrodes 2forming the scan electrodes and sustain electrodes cross with addresselectrodes 2 at approximately right angles. The circumferences ofsubstrates 1 and 5 are sealed, and the fine space is charged withdischarge gas formed of one of Helium, Neon, Argon and Xenon, or mixedgas of those gasses. Partitioning the discharge space with barrier ribs8 into plural sections provides plural discharge cells, in each of whichan intersection of display electrode 2 and address electrode 7 ispositioned. In each one of the discharge cells, phosphor layer 9 isplaced sequentially such that each cell is assigned to red, green andblue independently.

FIG. 2 illustrates a placement of the electrodes of this PDP. As shownin FIG. 2, the scan electrodes with the sustain electrodes and theaddress electrodes make a matrix of M lines×N rows. In a line direction,the scan electrodes SCN1 through SCNM and sustain electrodes SUS1through SUSM are arrayed in M lines. In a row direction, addresselectrodes D1 through DN are arrayed in N rows.

In the PDP having the foregoing electrode structure, a write-pulse isapplied between the address electrodes and the scan electrodes, so thataddress discharge is performed between the address electrodes and thescan electrodes for selecting discharge cells. Then, cyclic sustainpulses reversing alternately are applied between the scan electrodes andthe sustain electrodes, so that sustain discharge is performed fordisplaying a given indication.

FIG. 3 shows a timing chart of a display driving circuit of the plasmadisplay apparatus. As shown in FIG. 3, during an address period, eachone of sustain electrodes SUS1 through SUSM is held at 0 volt (V). Thena positive pulse voltage +Vw (V) is applied to given address-electrodesD1 through DN corresponding to the discharge cells indicating the firstline, and negative scanning pulse voltage −Vs (V) is applied to scanelectrode SCN1 corresponding to the first line. As a result,address-discharge occurs at the intersections of the givenaddress-electrodes D1 through DN and scan electrode SCN1 on the firstline.

Next, positive address-pulse voltage +Vw (V) is applied to givenaddress-electrodes D1 through DN corresponding to the discharge cellsindicating the second line, and negative scanning pulse voltage −Vs (V)is applied to scan electrode SCN2 assigned to the second line. As aresult, address-discharge occurs at the intersections of the givenaddress-electrodes D1 through DN and scan electrode SCN1 on the secondline.

Similar procedures to the above are sequentially carried out, andfinally positive address-pulse voltage +Vw (V) is applied to givenaddress-electrodes D1 through DN corresponding to the discharge cellsindicating the line M. Negative scanning pulse voltage −Vs (V) isapplied to scan electrode SCNM assigned to the line M. As a result,address-discharge occurs at the intersections of the givenaddress-electrodes D1 through DN and scan electrode SCNM on the line M.

During the next sustain period, each one of scan electrodes SCN1 throughSCNM is once held at 0 (V), and negative sustain pulse voltage −Vm (V)is applied to each one of sustain electrodes SUS1 through SUSM. As aresult, sustain discharge occurs between scan electrodes SCN1 throughSCNM and sustain electrodes SUS1 through SUSM at the intersections whereaddress discharge has occurred. Then, negative sustain pulse voltage −Vm(V) is applied alternately to all the scan electrodes SCN1 through SCNMand all the sustain electrodes SUS1 through SUSM, so that sustaindischarge occurs continuously at the discharge cells to be displayed.The light emission due to this sustain discharge makes the PDP display.

In the next erasing period, all scan electrodes SCN1 through SCNM areonce held at 0 (V), and erasing pulse voltage −Ve (V) is applied to allsustain electrodes SUS1 through SUSM. As a result, erasing dischargeoccurs to halt the discharging.

The foregoing operation is necessary for the plasma display apparatus todisplay one shot of video.

FIG. 4 shows an entire structure of a plasma display apparatusintegrating the foregoing PDP therein. In FIG. 4, the housing, whichaccommodates PDP 10, comprises front frame 11 and metallic back cover12. In the opening of front frame 11, front cover 13 formed of anoptical filter and glass that protect PDP 10 is placed. In order tosuppress interference radiation of electromagnetic waves, silverevaporation, for instance, is provided to front cover 13. Further,plural vent holes 12 a are provided to back cover 12 in order todissipate the heat generated in PDP 10 to the outside.

PDP 10 is bonded to a front face of chassis 14, made from aluminum, viaheat conductive sheet 15. On the rear side of chassis 14, plural circuitblocks 16 for driving and displaying PDP 10 are mounted. Heat conductivesheet 15 transfers the heat generated in PDP 10 to chassis 14efficiently for dissipating the heat. Circuit blocks 16 include electriccircuits that drive and display PDP 10 and control those operations.Circuit blocks 16 are electrically coupled to electrode-leads extendingto edges of PDP 10 via flexible wired boards (not shown) extending overthe four edges of chassis 14.

On the rear face of chassis 14, plural bosses 14 a are unitarily formedby die-casting. Bosses 14 a are used for mounting circuit blocks 16 andfixing back cover 12. Chassis 14 can be a flat aluminum plate with pinsfixed thereon.

FIG. 5 shows a plan view of the interior of the foregoing plasma displayapparatus viewed behind the apparatus with back cover 12 detached. InFIG. 5, scan driver circuit block 20 supplies a given signal voltage tothe scan electrodes of PDP 10, and sustain driver circuit block 21supplies a given signal voltage to the sustain electrodes of PDP 10.Address driver circuit block 22 supplies a given signal voltage to theaddress electrodes of PDP 10. Scan driver circuit block 20 and sustaindriver circuit block 21 are placed respectively on the either ends ofchassis 14 in a width direction. Address driver circuit blocks 22 areplaced on the upper and lower ends of chassis 14 in a height direction.

Control circuit block 23 converts video data, based on video signalssent from input signal circuit block 24, into video data signalsresponsive to the number of pixels of PDP 10 and supplies the video datasignals to address driver circuit block 22. Input signal circuit block24 is equipped with input terminals to which cables, connected to anexternal apparatus such as a television tuner, are connected detachably.Control circuit block 23 further generates a discharge control timingsignal and supplies it to scan driver circuit block 20 and sustaindriver circuit block 21, and is equipped with a display and drivecircuit block that controls display and drive such as controlling agray-scale. Control circuit block 23 is placed substantially at thecenter of chassis 14.

Power supply block 25 is disposed substantially at the center of chassis14 similar to control circuit block 23 and supplies the commercial powervoltage to the foregoing circuit blocks through power-supply input block27 that includes power cable connector 26 to which a power cable (notshown) is connected.

Bracket 28 is to be fixed to a stand pole, and is mounted on chassis 14at a lower end in a height direction. Tips of the stand pole mounted toa stationary stand are inserted into a hole of each bracket 28, and thestand pole is fixed to bracket 28 with screws, so that the stand is fitto the apparatus. As a result, the PDP is held in a standing posture.

Flexible wired board 29 couples the scan electrodes and leads of thesustain electrodes to the printed circuit boards of scan driver circuitblock 20 and sustain driver circuit block 21. Flexible wired board 30couples leads of the address electrodes to the printed circuit board ofaddress driver circuit block 22. Those flexible wired boards are bent180 degrees so that the boards are routed from the front side to theback side of PDP 10.

FIG. 6 and FIG. 7 show the structures of control circuit block 23 andinput signal circuit block 24. Those elements are detailed hereinafter.On circuit board 31 of block 23, a micro processor, a driver IC,electric circuit components and the like are mounted to form a givencontrol circuit. Control circuit block 23 is thus constructed. Circuitboard 31 is rigidly mounted to chassis 14 with screws substantially inparallel with PDP 10. On an edge of circuit board 31, signal inputtingconnectors 32 are placed, and signals are supplied from input signalcircuit block 24 through those connectors 32.

Input signal circuit block 24 is placed on chassis 14 approximately inparallel with PDP 10, and includes case 34, first signal-outputtingconnector 35 and first block unit 37. Case 34 has mounting port 33 opento the outside through back cover 12. First signal outputting connector35 is detachably coupled to case 34 via mounting port 33 thereby beingcoupled detachably to signal inputting connector 32 of control circuitblock 23. First block-unit 37 has first input-terminal 36 to which aconnection cable for coupling to an external apparatus is detachablycoupled.

Case 34 includes second block-unit 39 therein having second inputterminal 38 to which a connection cable, for coupling to anotherexternal apparatus such as a tuner or a personal computer, is detachablycoupled. Second signal outputting connector 40 is always coupled tosignal inputting connector 32 of control circuit block 23. Case 34 isomitted in FIG. 6, and first input terminal 36 and second block-unit 39are omitted in FIG. 7.

Case 34 is formed by bending a metal plate, and as shown in FIG. 7 andFIG. 8, the face thereof opposite to chassis 14 includes tabs 41unitarily formed with case 34 and disposed at various places. Tab 41 hasa mounting hole 41 a through which a screw extends for mounting case 34to chassis 14. Another face of case 34 substantially vertical to themounting face discussed above includes mounting port 33 and terminalport 43. Terminal port 43 has openings 42 to which second input-terminal38 of second block unit 39 built in case 34 are placed. Case 34 ismounted to chassis 14 through an opening (not shown) provided to backcover 12 with terminal port 43 exposed to the outside.

Protruding guide plate 44 is mounted on the inside wall of case 34extendedly in a direction vertical to mounting port 33. Guide plate 44is formed by bending a metal plate. When first block unit 37 is insertedinto case 34 through mounting port 33, first signal outputting connector35 of first block unit 37 is guided with guide plate 44 before it iseasily fit to signal inputting connector 32 of control circuit block 23.A first end of guide plate 44 has tapering section 44 a toward mountingport 33, and a second end has protrusion 44 b.

Upper face of case 34 is notched, and a section separated by the notchesis bent inside, which forms standing wall 45 inside case 34, so thatfirst block-unit 37 is partitioned from second block-unit 39 by standingwall 45, which also electromagnetically shields second block-unit 39.Second block-unit 39 placed in a shielded space surrounded by case 34and wall 45 is mounted to tabs 46 with screws.

FIG. 9 through FIG. 13 detail the structure of first block-unit 37. FIG.9 shows a top view, FIG. 10 shows a bottom view, FIG. 11 shows a lateralview, FIG. 12 shows a rear view from the side of first signal outputtingconnector 35, and FIG. 13 shows a front view from first input-terminal36 side.

First block-unit 37 electromagnetically shields circuit board 50, towhich electric circuit components and ICs forming input signal circuitsare mounted, and components, which form the input signal circuits andare mounted on the upper face of board 50. First block-unit 37 comprisesshielding plate 52 including recessed guide 51 which fits to guide plate44 mounted on the inside wall of case 34, and shielding plate 53 thatelectromagnetically shields the components forming the input signalcircuits mounted on a lower face of circuit board 50. The foregoing twoshielding plates 52, 53 are approximately the same size, and fixed tocircuit board 50 at the same position on board 50. Guide 51 of shieldingplate 52 is formed by recessing plate 52.

On an edge of circuit board 50, terminals of first signal outputtingconnectors 35 are electrically connected and fixed. On the edge of theother side of board 50, plural holes 54 a are formed so that first inputterminals 36 electrically connected to board 50 can extend through, andterminal plate 54 having U-shaped metal bracket 55 is mounted.

FIG. 14 and FIG. 15 show enlarged views illustrating in detail themounting of shielding plates 52 and 53 to circuit board 50. FIG. 14 isan enlarged view of section A in FIG. 9, and FIG. 15 is an enlarged viewof section B in FIG. 9.

As shown in FIGS. 9, 14 and 15, holes 50 a and 52 a for receiving screws56 are provided to circuit board 50 and shielding plate 52. Tapped hole53 a for receiving screw 56 is provided to shielding plate 53. Atsection A in FIG. 9, square holes 50 b and 52 b are provided adjacent tohole 50 a and 52 a to board 50 and plate 52, as shown in FIG. 14. Tab 53b is provided to plate 53 and inserted into square holes 50 b and 52 bfor positioning.

In other words, insertion of tab 53 b into square holes 50 b and 52 bprovided board 50 and plate 52 positions shielding plates 52 and 53 withrespect to circuit board 50. Then screw 56 extends through holes 50 aand 52 a provided to board 50 and plate 52 and is screwed in tapped hole53 a provided to shielding plate 53. As a result, shielding plates 52,53 can be positioned and mounted to circuit board 50 by only screw 56.

In the exemplary embodiment shown in FIG. 13, first block-unit 37 ofinput signal circuit block 24 uses 11 pin-jacks as first input terminal36 for receiving various apparatuses such as a VCR and a DVD player.However, it is not limited to this preparation, but it could be terminalplate 54 as shown in FIG. 16(a) through FIG. 16(f).

The example shown in FIG. 16(a) is equipped with only a connector asfirst input terminal 36 for connecting a cable to a tuner. In this case,second input terminal 38 of block-unit 39 in input-signal circuit block24 uses a connector to be coupled to a personal computer.

The example shown in FIG. 16(b) does not place first input terminal 36at terminal plate 54 of block-unit 37. In this case, an externalapparatus supplies signals only to second input terminal 38 ofblock-unit 39.

The examples shown in FIG. 16(c) through FIG. 16(f) have a longerterminal plate than those of the foregoing examples. The input terminalof FIG. 16(c) has the same structure as that shown in FIG. 13. In FIG.16(d), five pin-jacks and one connector are employed in first inputterminal 36. In FIG. 16(e), 12 pin-jacks are used as input terminals.FIG. 16(f) corresponds to FIG. 16(b), and no input terminals are placedon the side of block-unit 37.

As discussed in the foregoing exemplary embodiment, the presentinvention provides input signal circuit block 24 of a plasma displayapparatus, and this circuit block 24 comprises the following elements:

case 34 disposed on chassis 14 and having mounting port 33 open to theoutside of the housing; and

block-unit 37 equipped with first signal outputting connector 35detachably coupled to signal inputting connector 32 of the displaydriving circuit block, where this connector 35 is detachably fit to case34 via mounting port 33, so that connector 35 can be detachably coupledto connector 32, and also equipped with the input terminal to which aconnection cable to an external apparatus is detachably coupled.

The replacement of block-unit 37 of input-signal circuit block 24 allowsthe plasma display apparatus to be equipped with signal-input terminalsresponsive to a user's application.

In the present invention, case 34, to which block-unit 37 is mounteddetachably, is mounted to chassis 14 substantially in parallel with PDP10. Therefore, input-signal circuit block 24 formed of case 34 andblock-unit 37 can be placed utilizing the thickness of the plasmadisplay apparatus at the back side, so that overall thickness of theapparatus does not increase.

Further in the present invention, since block-unit 37 is detachablyplaced in case 34, block-unit 37 can be held by case 34. This structureprevents signal inputting connectors 32 and 35, where block-unit 37 iscoupled to control circuit block 32, from being stressed. Connectors 32and 35 are thus free from damage or unstable connections.

Block-unit 37 includes shielding plate 52 disposed on circuit board 50to which components forming an input signal circuit are provided.Shielding plate 52 is fitted to the inside wall of case 34 in whichblock-unit 37 is placed, so that guide plate 44 that positions theblock-unit is prepared. As a result, block-unit 37 is positioned beforeit is mounted smoothly in case 34.

As discussed in the embodiment, the two shielding plates 52 and 53 aresubstantially in the same size, and they are fixed to circuit board 50at the same position on board 50. This structure allows the twoshielding plates to be mounted on both the sides of board 50 at onetime, yet, at the same position, so that space saving is achievable.

INDUSTRIAL APPLICABILITY

The present invention provides a plasma display apparatus that providesa user with signal input terminals appropriate to a user's need bysimply replacing a block-unit of an input signal circuit block. Theblock-unit is detachably placed in a case, so that the case holds theblock-unit. This structure prevents a connector from damage or unstableconnection because stress concentrates on the connector where theblock-unit is coupled to a control circuit block.

The block-unit includes a guide plate disposed on a circuit board wherecomponents forming the input signal circuit are mounted, and the guideplate is fitted to the inside wall of the case to which the block-unitis mounted, whereby the block-unit can be positioned. This guidingstructure allows the block-unit to be positioned before the block-unitis mounted smoothly in the case.

1-12. (canceled)
 13. A plasma display apparatus comprising: a panel including a front substrate and a rear substrate, at least said front substrate being transparent, placed opposite to each other to form a discharge space therebetween, and a plurality of electrodes provided to said front and rear substrates; a display driving circuit block having a signal inputting connector, said display driving circuit block for applying a signal to said panel to perform displaying thereon, and said display driving circuit being disposed on a chassis; an input signal circuit block detachably coupled to said display driving circuit block and adapted to receive a video signal from an external apparatus; and a housing for accommodating said panel, said display driving circuit block and said input signal circuit block, wherein said input signal circuit block is provided to the chassis, and includes: a case having a mounting port open to outside of said housing; and a block-unit having a signal outputting connector mounted detachably to said case via said mounting port, said signal outputting connector being detachably coupled to said signal inputting connector of said display driving circuit block when said signal outputting connector is mounted to said case, and having an input terminal adapted to be detachably coupled to a connection cable for coupling to the external apparatus; wherein said block-unit includes a circuit board having electronic components forming an electronic circuit on both surfaces thereof, and upper and lower metal plates respectively mounted to said surfaces of said circuit board such that said upper and lower metal plates cover the electronic components for electromagnetically shielding the electronic components and dissipating heat generated from the electronic components, and wherein the upper and lower metal plates have substantially the same size and are mounted to said circuit board by being fixed at an identical position on said circuit board.
 14. The plasma display apparatus as defined in claim 13, wherein a positioning tab, to be inserted in a hole punched on the circuit board, is provided to a first metal plate of the upper and lower metal plates, and a second metal plate has a hole, to be inserted with the positioning tab, at an identical place to the hole of the circuit board.
 15. The plasma display apparatus as defined in claim 13, wherein holes, through which a screw is inserted, are provided to the circuit board and a first metal plate of the upper and lower metal plates, and a second metal plate has a tapped hole for accepting the screw, wherein the screw extends through the hole from the first metal plate and engages the tapped hole of the second metal plate for fixing the upper and lower metal plates to the circuit board. 